SAN FRANCISCO — Welp, we finally learned what LinkedIn’s doing with Rapportive, the email plugin it bought last year.

It’s now called LinkedIn Intro. Like Rapportive, it skims web-based data from social networks and other sources to create on-the-fly profiles of the people who email you.

From your email, you tap a button, and you can see a full professional history, schooling, location, etc., for anyone who sends you a message. This will ostensibly make you a more insightful, thoughtful, omniscient correspondent. Not a creeper.

Actually, if you’re a particularly thorough business email user, you probably do this a lot from your desktop: Get an email, conduct some light stalking via LinkedIn and Google, and use that info to decide how (or whether) to respond.

Intro just makes it easier to do that from your phone, where you’re constantly fielding email.

Here’s a sneak peek:

If this sounds like something you want, check out Intro.LinkedIn.com. It works for Gmail, Google Apps, Yahoo Mail, Apple Mail, etc.

If this sounds like something that creeps you out, well, it’s your own dang fault for putting your personal information on the searchable Internet. You can remove yourself from the web, but that cat’s already out of the proverbial bag.

Intro is part of LinkedIn’s sprawling and freshly updated mobile suite — and it’s part of CEO Jeff Weiner’s long-term goal to take over the world with 3 billion profiles and a global economic map.